Orthoporus ornatus is a North American species of millipede in the family Spirostreptidae that can be found in the U.S. states of Arizona, New Mexico and Texas, and as far south as the Mexican state of San Luis Potosí. They became very popular in the pet trade and many were exported to Western Europe. Brian Van Der Kieft and Max Prins were the first breeders of this species in Europe. Individuals on average are 4 inches (10 cm) in length, but can either be as small as 3 inches (76 mm), or exceed up to 9 inches (230 mm) in length. They are dark brownish coloured, but can sometimes be yellow. In fact, in every state the species looks different. The antennae are located near the organs of Tömösváry. The species feed on both living and dead organic material. The species prefer sunshine, but can be seen on summer rainy days as well. A disturbed Orthoporus ornatus may curl into a coil and release a toxic substance from glands that are located along the sides of their body segments. The species can live more than ten years. The species feed on shrubs of Ephedra, which grows in Jornada del Muerto, and on Salsola that grows in Albuquerque.